A novel and sensitive amperometric hydrazine sensor based on gold nanoparticles decorated graphite nanosheets modified screen printed carbon electrode

• Amperometric hydrazine sensor based on activated graphite/gold nanoparticles (AG/Au-NPs) composite modified screen printed carbon electrode.
• The AG/Au-NPs composite has been synthesized by electrochemical method.
• A fast amperometric response with lower LOD of 0.57 ± 0.03 nM has been achived.

A highly sensitive amperometric hydrazine sensor has been developed for the first time using gold nanoparticles (Au-NPs) decorated activated graphite (AG) modified screen printed carbon electrode (SPCE). The preparation of AG and decoration of Au-NPs on AG surface involve simple electrochemical methods. AG/Au-NPs composite modified electrode shows a higher catalytic response and lower overpotential for hydrazine compared to Au-NPs decorated on activated SPCE and/or graphite SPCE. The response of the sensor for hydrazine detection lies within 2 s, indicating an excellent electrocatalytic ability of the composite electrode. The lowest limit of detection (LOD) of 0.57 ± 0.03 nM is able to be achieved using AG/Au-NPs electrode, which is the lowest LOD that has ever been reported in the literature for hydrazine. Under optimum condition, the fabricated AG/Au-NPs composite exhibits a wider linear response for hydrazine detection up to 936 μM. The sensor shows a very good sensitivity along with an excellent operational stability. The sensor proves its superior selectivity even in the presence of 1000 and 200 folds of common metal ions and biologically co-active interfering species.